This invention relates to apparatus for selectively segmenting white blood corpuscles and red blood corpuscles in blood.
Clinical examination of blood usually performed includes hematrocrit measurement, hemoglobin measurement, counting of the number of red blood corpuscles, counting of the number of white blood corpuscles, counting of the number of serums, counting of the number of the reticulocytes and identification and counting of the number of white blood corpuscles. Of these number of methods since the method of calculating the number of the reticulocytes and the method of identifying and calculating the number of white blood corpuscles require to identify the form of pattern of the reticulocytes and white blood corpuscles it is extremely difficult to perform such examinations by automatic apparatus.
In order to identify the pattern of a blood corpuscle image it is necessary to firstly segment a desired blood corpuscle image. For example, for the purpose of discriminating white blood corpuscles it is necessary to remove the red blood corpuscles from blood corpuscles containing both red and white blood corpuscles and then to obtain the image of only the white blood corpuscles. Since the result of detection and segmentation of specific type of the blood corpuscles directly influences the result of discrimination, development of improved segmentation means has long been desired.
According to one prior method a medicament is added to blood comprising a mixture of red and white blood corpuscles for the purpose of chemically destroying the red blood corpuscles along. According to this method, however, some of the white blood corpuscles in the sample are also deformed. Further, as it is necessary to stain the sample after incorporation of the medicament the form of the resulting sample becomes different from the standard form presently used widely so that there is an inconvenience that it is necessary to prepare again the sample for the next observation. Further, this method is difficult to completely remove the red blood corpuscles thus leaving some of them. This results in an error in the calculated number of the white blood corpuscles.
According to another method, use is made of a three filters corresponding to three primary colors, wherein respective picture elements of the blood corpuscle image which are obtained by the analytic action of the three primary colour filter are displayed as spots in a three dimentional vector space so as to discriminate the white and red blood corpuscles according to the positions of the spots in said space. According to this method although it is possible to preserve the form of ordinary samples it is necessary to use a large capacity memory device capable of storing various tones of respective images corresponding to respective dimensions produced by the three primary color filter. Moreover, as it is necessary to use a high speed digital-analogue converter for the memory device the apparatus is bulky and expensive.